A Pennsylvania firm has opened a new plant to treat and recycle wastewater generated by Marcellus shale natural gas drilling.

Aquatech International Corp., which is based in Canonsburg, says the new plant opened in Tioga County on Wednesday. That's in northeast Pennsylvania near the New York border.

The company says the Tioga facility has a central treatment plant that uses a combination of technologies to treat drilling fluids, the highly salty brine that flows back from wells, and other oil and natural gas wastewaters.

Critics of gas drilling, or fracking, are concerned about the huge amounts of wastewater generated by a recent drilling boom.

Treated wastewater can be reused in other wells, thus reducing the amount of fresh water that drillers use to fracture, or stimulate, well production.